BrooksPW
New member
I like Gutter Grenade because it takes the black streaks off but won't take off any paint because it only removes the oxidized finish.
Anything else I have tried tends to take the paint with the streaks. Mix it a little too strong and you're painting gutters for free.
Mix to strong and you'll have that white paint dripping all over! F-13 is the best!!! a little bit goes a long way..